Changes in soil N pools in response to earthworm population manipulations in agroecosystems with different N sources

abonos nitrogenados abonos verdes ammonium nitrate azote bovin cattle cover plants cycling earthworms engrais organique engrais vert farmyard manure fumier ganado bovino green manures leaching legumes leguminosas lessivage du sol lolium nitrate nitrate d'ammonium nitrates nitrato de amonio nitratos nitrogen nitrogen balance nitrogen fertilizers nitrogen metabolism oligochaeta organic fertilizers plantas de cobertura plante de couverture population density riesgo risk risque soil sol suelo